Impregnating material for shoe linings



Sept., 22, 1936- w. sTELKENsl IMREGNTING MATERIAL FOR SHOE LININGS Filed Feb. ll, 1933 uboneonuo noovoooo oo nooo oooooo oooooo oooooo cono ooe oooooo o o o o fama ,wf/mam@ Patented .Sept. 22, 1936 PATENT ori-lcs rMPREGNATING MATERIAL FOR SHOE )LININ Willy Stelkens, Cologne, "Germany, assignor to C. F. Boehringer & Soehne Gr. m. b. H., Mannheim-.Waldhof, Germany Application February 11, 1933,' serial No. 656,320. In GermanyeAugust 25, 1932 v10 claims.

My invention relates to impregnating materials adapted for use in imparting stiffness to certain parts of boots and shoes and more especially to the'llnings ofl the toe-caps or tips and the heel counters. It is an object .of my invention to provide a material fit for use in the stifening of these linings, which', while being at least equ'ally efficient as the stiieners hitherto suggested, offers particular advantages regarding the saving of time and labor. I i.

As is well known to those skilled in the art, in order to impart to certain parts of shoes and boots and more especially to the toe-caps and to the heel counters a particular stiffness, the shoes and bootsare reinforced at these places with inserts of a particular kind, for instance by ce' menting into the shoe or boot at the place -to be reinforced a plurality of layers of fabric; using therefor a solution of an agglutinant such as celcelluloid or of some other agglutinat which solidifles on drying, to; stiffen it sufficiently, the

solution must be spread on the fabric repeatedly. Obviously much time is consumed in this operation and comparatively largequantities of solvvents must be evaporated. Therefore, instead of first spreading a solution of an agglutinant on the fabric and thereafter fixing this piece of fabric in place, I have adopted, more particularly in mass production, a different procedure: The stiiener material is prepared beforehand by combining the fabric forming the insert with a solid agglutinant, and this material, which is thus prepared ready for use, is then cemented in between the linings of the shaft. A stiffening material of. this kind may be produced either by Acementing a plurality of layers of strong fabric together by means of liquid agglutinants or by immersing such a' ifles on drying. Alternatively a fabric being suiciently strong as such to stiften the caps etc. may be provided on either surface with a thin layer of anagglutinant suflcing to cement it to the 4lining of. the shoe. The first of these processes again involves the drawbacks mentioned above, viz. loss of time. and solvents. In the last-mentioned case the thickness of the stiffener material renders it necessary to sharpen it at the edges by hand in order to avoid the formation lof ,hard-uneven'.l projections exerting pressure on the toes and heel of the bearer.

In order to avoid the sharpening Aof the edges one might simply insert folia of celluloid or' some similar material in slightly swollen condition beluloid to fix the fabric in place. In order to in-l corporatein .the fabricsuficient quantities of fabric in a solution of an agglutinant which solidtween the fabric lining the shaft of. the shoe. A material of this kind would render the sharpening operation superfluous since the pressure ap- 'plied to the material would cause some of the agglutinant to cover the projecting edges. Apart therefrom the cuttings resulting in the manufacture of this stiifening material might be utilized forother purposes. However the pressure required to firmly unite the lining placed on the last with the softened celluloid also effects 'adisplacement of the celluloid at the curved points of the last, which are exposed to the greatest pressure, and a similar displacement of. the ce1- luloid takes place before the pinching, the film of agglutinant becoming too thin at these places and being torn ofi.

I have now found that if a film or folium of the agglutinant, such as celluloid, is combined with a' layer of fibrous material, such as a light and thin open-textured fabric, the drawbacks mentioned above as connected with the use of simple celluloid are done away with, while the drawbacks connected with the use of the well known stiffeners do not arise.` I have found that the layer of fibrous material united with the celluloid or the like prevents the agglutinant from being displaced ,by the pressure acting upon it,

` before the agglutinant has had time to enter and impregnate the linings between which it has been inserted. In contradistinction tothe known 'stiffeners mentioned above, in which a stiff fabric is relied upon to stiffen the cap or heel piece, the thin layers of celluloid merely serving for .cementing the stiiener material to the lining, the thin layer of fibrous material combined with the agglutinant according-to the present invention merely serves for retaining the agglutinant, while this latter, being softened by swelling, permeates the linings between which it has been inserted and on solidifying imparts to them the required stiffness.'

In view of this actionA of the layer of fibrous material the proportion of such material as compared with the weight of the agglutinant combined with it is distinguished from similar combinations in that the weight of the fibrous material is less than one fourth of the weight of the agglutinant or not more and in many cases less than 20% of the total weight of the cementing. material, being reducible for instance to 10 per cent of the whole.

obviously, besides the combination er e single folium of agglutinant with a single layer of flbrous material, I may also combine a layer of such light and thin fibrous material with two light and thin fabric provided with wide meshes so as to be readily permeable for the agglutinant when softened by contact with a solvent or swelling agent. On the combined layers being inserted between two layers of lining, the agglutinant will readily permeate the lining and stiffen and cement it in place.

The cuttings of an impregnating and stifening material of this kind can readily be put to further use, similarly as cuttings of pure celluloid folia, in contradistinction to the known stiffeners bein combinations of iibrous material and celluloid or the like, comprising comparatively heavy and dense fabrics, which cannot be reused and must therefore be got rid of by burning them, which in cases where celluloid forms the agglutinant layer, must be done with caution. The cuttings of a material according to this invention, which comprises a light wide-meshed fabric, can be returned into the process of manufacture, since the light fabric can be stripped from the layer of celluloid by means of solvents and can be separated from the celluloid in the filter press, so that a compound material of this kind also offers further economical advantages.

I may use many kinds of fabrics and more especially wide-meshed fabrics readily permeable for the softened agglutinant, more especially light upholstering nettle cloth, gauze and the like. As to the agglutinant, I prefer using a film or folium of a cellulose derivative, in which may be incorporated a suitable plasticizer, such film aor folium consisting for instance of celluloid, celluloid cuttings, nitrocellulose, cellulose acetate or cuttings of such compounds, of masses containing cellulose acetate including cellon cuttings, of acetate silk cuttings or of mixed celluloseesters and ethers or mixtures of such,` asr described for instance in a copending application for patent of the United States, Serial No. 474,- 301, filed by myself and Richard Mller jointly, which may be mixed with each other or lwith foreign additions such as kaolin, but also of other jelly-forming material. These compounds may still contain some of the fluid solvents or swelling agents admixed with them during manufacture, so that according to the percentage, which may for instance vary between 10 and 25%, calculated on the dry weight of the film or folium, the pieces of cementing material cut to shape can be fixed in place in the shoes or boots with small quantities of fiuid or vaporous solvents or swelling agents only, or even without suchsolvents or swelling agents, by merely applying heat and pressure.

methyl alcohol or the like, `or mixtures thereoff;

being fixed in the shoe by pressure'. Instead of immersing it in-the solvent orswelling agent,'

these solvents or swelling agentsmay also be lspread or sprayed on the compound material The cementlng material may however also be immersed in a suitable solvent or or on the places in the shoe to which it shall be applied, or the agglutinant may be softened by the action of vapors of volatile solvents. I may also fix the new material in the bo'ot or shoe at a temperature above normal.

y I may further improve the impregnating material according to the present invention by forming the film or filmsof agglutinant with indentures or perforations, which may also extend across the layer of iibrous'material, and I thereby obtain that the film or folia of agglutinant being acted upon by a solvent or swelling agent will soften more readily than compact plain folia, the film or folia being converted quickly into a tough sticky jelly, which under the action of mechanical pressure applied to it will expand more evenly than plain folia, the indentures or perforations being filled with the agglutinant, which also spreads over the edges of the toe cap or heel counter, covering the projecting edges and sloping towards the shaft. The indentures may preferably have the form of furrows ormay have theV form of a Wafer pattern. If the film or folia is perforated, these perforations may extend right across the compound material and in this latter case care must be taken to employ a fabric, the threads of which are protected as far as possible against being cut or severed when perforating the material, since the threads must retain their mechanical resistivity in order to enable them to withstand the subsequent pinching operation.

I may for instance combine a film of celluloid containing about 20% camphor and weighing about 500 grams per square metre with a widemeshed nettle cloth weighing to 120 grams per square metre, the cloth being moistened with ethyl acetate and the celluloid lm being formed, on its free.side, together with the fibrous layer, with indentures by' means of a heated engraved cylinder. When produced in this manner the agglutinant merely adheres to the surface vof the light fabric without substantially impregnating the same.

Pieces of this compound material cut to size are immersed in ethyl acetate to cause swelling of the agglutinant and are then. inserted for instance between the linings of a toe tip. The shaft of the shoe is `now mounted under tension in place on the wooden last serving to impart to the tip the proper shape and is pinched. The toe tip or cap is left on the last until it has become and hard.

y On removing the last, the celluloid will be found to have permeated the linings on both sides, having imparted to them a uniform stiffness and having thoroughly cemented them to the leather, the edges, instead of projecting, being formed with a gradual slope.

In the drawing afiixed to this specification and forming part thereof,

Fig. 1 illustrates the combination of a single layer of fabric with a singlefolium of agglutinant,

Fig. 2- shows a folium enclosed between two layers of fabric,

Fig. 3 a lay of fabric enclosed between two folia, y

Fig. 4 isa modification of the article shown lin Fig. 1, theV foliumbeing perforated;

Fig. 5 is a similar modification, wherein the perforations extend also through the fabric; A

Fig. 6 shows the article of Fig. 1 modied by' indentures forming a waferpattern, and

Fig. 7 is a modification of the article shown in Fig. 6, showing perforations extending across both Various changes may be made in Athed-etails disclosed in the foregoing -specication without the , swelling agent and of hardening on drying, with a sheet of brous material adhering to one sur'- face of said folium,said sheet being so thin and` light and of suchloose texture as to be readily permeable to the softened agglutinant and to be incapable of exerting any appreciable stiffening action, when impregnated with agglutinant.

2; A- sheeted adhesive useful for' cementing and stiifening the linings of boots and shoes, comprising in combination at least one folium of an adhesive cellulose derivative being substantially water proof ybut becoming tacky in the presence oi.

said cellulose derivative in position when said adhesive sheet is pressed between said4 linings while in softened condition; said cellulose derivative adhering tol said fabric without substantially impregnating the same until applied in use.y

3. The sheeted adhesive of claim 2 wherein said fabric material forms not substantially more than about'onefthird the total weight of said adhesive sheet. 4f The sheeted adhesive of claim 2 wherein said adhesive is formed of a single folium of cellulose derivative enclosed between two layers of said fabric material.

5. The sheeted adhesive of claim 2 wherein said adhesive is formed of a single layer of fabric .material enclosed between folia of saidcellulose derivative."

6. The sheeted adhesive of claim 2 wherein said cellulose derivative is pierced with perforay tions increasing its surface area.

7. rllhe sheeted adhesive of claim 2 wherein said cellulose derivative is formed with indentures and perforations increasing its superficial area.

8. The sheeted adhesive of claim 2 wherein the folium of cellulose derivative extendsbeyond the layer of fibrous material.

9. The sheeted adhesive of claim 2- wherein said cellulosederivative contains a small amount of organic softening agent, v

10. The sheeted adhesive of claim 2 `wherein said cellulose derivative is celluloid.

Y s'rELKENs. 

